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dxt.js
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dxt.js
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const BLOCK_SIZE = 16;
const BLOCK_SIZE_4 = 4;
const BLOCK_SIZE_4X4 = 16;
const BLOCK_SIZE_4X4X4 = 64;
const CHANNEL_SIZE_ARGB = 4;
const CMP_Speed_Normal = 1;
const CMP_Speed_Fast = 0;
var m_fChannelWeights = [];
var m_fBaseChannelWeights = [];
var m_bUseChannelWeighting = true;
var m_bUseAdaptiveWeighting = true;
var m_bSwizzleChannels = false;
var m_nCompressionSpeed = CMP_Speed_Normal;
var m_nCompressionSpeedAlpha = CMP_Speed_Normal;
const RG = 5;
const GG = 6;
const BG = 5;
var m_bUseSSE2 = false;
var m_b3DRefinement = true;
var m_nRefinementSteps = 1;
const NUM_CHANNELS = 4;
const RGB_CHANNELS = 3;
const NUM_ENDPOINTS = 2;
const MAX_BLOCK = 16;
const MAX_POINTS = 16;
const AC = 3
const RC = 2
const GC = 1
const BC = 0
const PIX_GRID = 8;
const FLT_MAX = Number.MAX_VALUE;
const FLT_MIN = Number.MIN_VALUE;
const CE_OK = 0;
const CE_Aborted = 2;
const CE_Unknown = 1;
const EPS = (2 / 255.0) * (2.0 / 255.0)
const EPS2 = 3 * (2.0 / 255.0) * (2.0 / 255.0)
const MAX_ERROR = 128000;
const GBL_SCH_STEP_MXS =0.018
const GBL_SCH_EXT_MXS =0.1
const LCL_SCH_STEP_MXS =0.6
const GBL_SCH_STEP_MXQ =0.0175
const GBL_SCH_EXT_MXQ =0.154
const LCL_SCH_STEP_MXQ =0.45
const GBL_SCH_STEP =GBL_SCH_STEP_MXS
const GBL_SCH_EXT =GBL_SCH_EXT_MXS
const LCL_SCH_STEP =LCL_SCH_STEP_MXS
var m_nRefinementStepsAlpha = 3;
m_fChannelWeights[0] = m_fBaseChannelWeights[0] = 0.3086;
m_fChannelWeights[1] = m_fBaseChannelWeights[1] = 0.6094;
m_fChannelWeights[2] = m_fBaseChannelWeights[2] = 0.0820;
const nByteBitsMask =
[
0x00,
0x80,
0xc0,
0xe0,
0xf0,
0xf8,
0xfc,
0xfe,
0xff,
]
var Fctrsr = new Float32Array(3);
Fctrsr[RC] = (1 << RG);
Fctrsr[GC] = (1 << GG);
Fctrsr[BC] = (1 << BG);
var Fctrs = new Float32Array(3);
Fctrs[RC] = (1 << (PIX_GRID - RG));
Fctrs[GC] = (1 << (PIX_GRID - GG));
Fctrs[BC] = (1 << (PIX_GRID - BG));
var Rpt = new Float32Array(BLOCK_SIZE);
var BlkIn = new Float32Array(BLOCK_SIZE * NUM_CHANNELS);
var dwBlk = new Float32Array(BLOCK_SIZE);
var InpRmp = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
var nEndpoints1 = new Uint8Array(RGB_CHANNELS * NUM_ENDPOINTS);
var nEndpoints2 = new Uint8Array(RGB_CHANNELS * NUM_ENDPOINTS);
var nIndices1 = new Uint8Array(BLOCK_SIZE_4X4);
var nIndices2 = new Uint8Array(BLOCK_SIZE_4X4);
var nEndpoints = new Uint8Array(RGB_CHANNELS * NUM_ENDPOINTS);
var nIndices = new Uint8Array(BLOCK_SIZE_4X4);
var Blk = new Float32Array(MAX_BLOCK * NUM_CHANNELS);
var rsltC = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
var dwBlkU = new Int32Array(BLOCK_SIZE);
var InpRmp = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
var Rmp = new Float32Array(NUM_CHANNELS * MAX_POINTS);
var Prj0 = new Float32Array(MAX_BLOCK);
var Prj = new Float32Array(MAX_BLOCK);
var PrjErr = new Float32Array(MAX_BLOCK);
var LineDir = new Float32Array(NUM_CHANNELS);
var RmpIndxs = new Float32Array(MAX_BLOCK);
var LineDirG = new Float32Array(NUM_CHANNELS);
var PosG = new Float32Array(NUM_ENDPOINTS);
var Blk = new Float32Array(MAX_BLOCK * NUM_CHANNELS);
var BlkSh = new Float32Array(MAX_BLOCK * NUM_CHANNELS);
var LineDir0 = new Float32Array(NUM_CHANNELS);
var Mdl = new Float32Array(NUM_CHANNELS);
var rsltC = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
var PrjBnd = new Float32Array(NUM_ENDPOINTS);
var BlkPr1 = new Uint8Array(MAX_BLOCK * NUM_CHANNELS);
var BlkPr2 = new Uint8Array(MAX_BLOCK * NUM_CHANNELS);
var BlkPrAlpha1 = new Uint8Array(MAX_BLOCK);
var BlkPrAlpha2 = new Uint8Array(MAX_BLOCK);
//align16 float
var PreMRep = new Float32Array(MAX_BLOCK);
function ConstructColour(r, g, b) { return (((r) << 11) | ((g) << 5) | (b)) }
function toUnsigned(value) {
if (value >= 0)
return value;
else
return value + 4294967296;
}
function memset(arr, value) {
var dim = Array.isArray(arr[0]);
if (dim)
for (var i = 0; i < arr.length; i++) {
memset(arr[i], value);
}
else
for (var i = 0; i < arr.length; i++) {
arr[i] = value;
}
}
function createArray(length) {
var arr = new Array(length || 0),
i = length;
if (arguments.length > 1) {
var args = Array.prototype.slice.call(arguments, 1);
while (i--) arr[length - 1 - i] = createArray.apply(this, args);
}
return arr;
}
function QSortIntCmp(Elem1, Elem2) {
return (Elem1 - Elem2);
}
function Compress(bufferIn, bufferOut, pFeedbackProc, pUser1, pUser2) {
assert(bufferIn.GetWidth() == bufferOut.GetWidth());
assert(bufferIn.GetHeight() == bufferOut.GetHeight());
if (bufferIn.GetWidth() != bufferOut.GetWidth() || bufferIn.GetHeight() != bufferOut.GetHeight())
return CE_Unknown;
const dwBlocksX = ((bufferIn.GetWidth() + 3) >>> 2);
const dwBlocksY = ((bufferIn.GetHeight() + 3) >>> 2);
var bUseFixed = (!bufferIn.IsFloat() && bufferIn.GetChannelDepth() == 8 && !m_bUseFloat);
var fAlphaThreshold = CONVERT_BYTE_TO_FLOAT(m_nAlphaThreshold);
for (var j = 0; j < dwBlocksY; j++) {
for (var i = 0; i < dwBlocksX; i++) {
var compressedBlock = createArray(2);
if (bUseFixed) {
var srcBlock = createArray(BLOCK_SIZE_4X4X4);
bufferIn.ReadBlockRGBA(i * 4, j * 4, 4, 4, srcBlock);
CompressRGBBlock(srcBlock, compressedBlock, CalculateColourWeightings(srcBlock), true, m_bDXT1UseAlpha, m_nAlphaThreshold);
}
else {
var srcBlock = createArray(BLOCK_SIZE_4X4X4);
bufferIn.ReadBlockRGBA(i * 4, j * 4, 4, 4, srcBlock);
CompressRGBBlock(srcBlock, compressedBlock, CalculateColourWeightings(srcBlock), true, m_bDXT1UseAlpha, fAlphaThreshold);
}
bufferOut.WriteBlock(i * 4, j * 4, compressedBlock, 2);
}
if (pFeedbackProc) {
var fProgress = 100.0 * (j * dwBlocksX) / (dwBlocksX * dwBlocksY);
if (pFeedbackProc(fProgress, pUser1, pUser2))
return CE_Aborted;
}
}
return CE_OK;
}
function CalculateColourWeightings(block) {
if (!m_bUseChannelWeighting)
return NULL;
if (m_bUseAdaptiveWeighting) {
medianR = 0.0, medianG = 0.0, medianB = 0.0;
for (var k = 0; k < BLOCK_SIZE_4X4; k++) {
var R = (block[k] & 0xff0000) >>> 16;
var G = (block[k] & 0xff00) >>> 8;
var B = block[k] & 0xff;
medianR += R;
medianG += G;
medianB += B;
}
medianR /= BLOCK_SIZE_4X4;
medianG /= BLOCK_SIZE_4X4;
medianB /= BLOCK_SIZE_4X4;
// Now skew the colour weightings based on the gravity center of the block
var largest = Math.max(Math.max(medianR, medianG), medianB);
if (largest > 0) {
medianR /= largest;
medianG /= largest;
medianB /= largest;
}
else
medianR = medianG = medianB = 1.0;
// Scale weightings back up to 1.0f
var fWeightScale = 1.0 / (m_fBaseChannelWeights[0] + m_fBaseChannelWeights[1] + m_fBaseChannelWeights[2]);
m_fChannelWeights[0] = m_fBaseChannelWeights[0] * fWeightScale;
m_fChannelWeights[1] = m_fBaseChannelWeights[1] * fWeightScale;
m_fChannelWeights[2] = m_fBaseChannelWeights[2] * fWeightScale;
m_fChannelWeights[0] = ((m_fChannelWeights[0] * 3 * medianR) + m_fChannelWeights[0]) * 0.25;
m_fChannelWeights[1] = ((m_fChannelWeights[1] * 3 * medianG) + m_fChannelWeights[1]) * 0.25;
m_fChannelWeights[2] = ((m_fChannelWeights[2] * 3 * medianB) + m_fChannelWeights[2]) * 0.25;
fWeightScale = 1.0 / (m_fChannelWeights[0] + m_fChannelWeights[1] + m_fChannelWeights[2]);
m_fChannelWeights[0] *= fWeightScale;
m_fChannelWeights[1] *= fWeightScale;
m_fChannelWeights[2] *= fWeightScale;
}
return m_fChannelWeights;
}
//byte[], dword[], float, bool, bool
function CompressRGBBlock(rgbBlock, compressedBlock, pfChannelWeights, bDXT1, bDXT1UseAlpha, nDXT1AlphaThreshold, blkPrv) {
/*
ARGB Channel indexes
*/
var RC = 2, GC = 1, BC = 0;
if (m_bSwizzleChannels) {
RC = 0; GC = 1; BC = 2;
}
if (bDXT1 && m_nCompressionSpeed == CMP_Speed_Normal) {
//byte, byte
var nEndpointsl, nIndicesl;
//rgb, num
// var nEndpoints1 = new Uint8Array(RGB_CHANNELS * NUM_ENDPOINTS);
// var nEndpoints2 = new Uint8Array(RGB_CHANNELS * NUM_ENDPOINTS);
// var nIndices1 = new Uint8Array(BLOCK_SIZE_4X4);
// var nIndices2 = new Uint8Array(BLOCK_SIZE_4X4);
//double
if (bDXT1UseAlpha){
BlkPr1.fill(0);
BlkPr2.fill(0);
}
else {
for (var i = 0; i < 16; i++){
BlkPr1[i*4]=0;
BlkPr1[i*4+1]=0;
BlkPr1[i*4+2]=0;
BlkPr1[i*4+3]=(rgbBlock[i]>>>24);
BlkPr2[i*4]=0;
BlkPr2[i*4+1]=0;
BlkPr2[i*4+2]=0;
BlkPr2[i*4+3]=(rgbBlock[i]>>>24);
}
}
var fError3 = CompRGBBlock(rgbBlock, BLOCK_SIZE_4X4, RG, GG, BG, nEndpoints1, nIndices1, 3, m_bUseSSE2, m_b3DRefinement, m_nRefinementSteps, pfChannelWeights, bDXT1UseAlpha, nDXT1AlphaThreshold, BlkPr1);
var fError4 = (fError3 == 0.0) ? FLT_MAX : CompRGBBlock(rgbBlock, BLOCK_SIZE_4X4, RG, GG, BG, nEndpoints2, nIndices2, 4, m_bUseSSE2, m_b3DRefinement, m_nRefinementSteps, pfChannelWeights, bDXT1UseAlpha, nDXT1AlphaThreshold, BlkPr2);
//uint
var nMethod = fError3 <= fError4;
if (nMethod) {
nEndpointsl = nEndpoints1;
nIndicesl = nIndices1;
blkPrv.set(BlkPr1);
}
else {
nEndpointsl = nEndpoints2;
nIndicesl = nIndices2;
blkPrv.set(BlkPr2);
}
var c0 = ConstructColour((nEndpointsl[RC * NUM_ENDPOINTS] >>> (8 - RG)), (nEndpointsl[GC * NUM_ENDPOINTS] >>> (8 - GG)), (nEndpointsl[BC * NUM_ENDPOINTS] >>> (8 - BG)));
var c1 = ConstructColour((nEndpointsl[RC * NUM_ENDPOINTS + 1] >>> (8 - RG)), (nEndpointsl[GC * NUM_ENDPOINTS + 1] >>> (8 - GG)), (nEndpointsl[BC * NUM_ENDPOINTS + 1] >>> (8 - BG)));
if (!nMethod && c0 <= c1 || nMethod && c0 > c1)
compressedBlock[0] = (c1 | (c0 << 16));
else
compressedBlock[0] = (c0 | (c1 << 16));
compressedBlock[1] = 0;
for (var i = 0; i < 16; i++)
compressedBlock[1] = compressedBlock[1] | (nIndicesl[i] << (2 * i));
}
else {
//byte
//var nEndpoints = new Uint8Array(RGB_CHANNELS * NUM_ENDPOINTS);
//var nIndices = new Uint8Array(BLOCK_SIZE_4X4);
if (bDXT1UseAlpha){
blkPrv.fill(0);
}
else {
for (var i = 0; i < 16; i++){
blkPrv[i*4]=0;
blkPrv[i*4+1]=0;
blkPrv[i*4+2]=0;
blkPrv[i*4+3]=(rgbBlock[i]>>>24);
}
}
CompRGBBlock(rgbBlock, BLOCK_SIZE_4X4, RG, GG, BG, nEndpoints, nIndices, 4, m_bUseSSE2, m_b3DRefinement, m_nRefinementSteps, pfChannelWeights, bDXT1UseAlpha, nDXT1AlphaThreshold, blkPrv);
//uint
var c0 = ConstructColour((nEndpoints[RC * NUM_ENDPOINTS] >>> (8 - RG)), (nEndpoints[GC * NUM_ENDPOINTS] >>> (8 - GG)), (nEndpoints[BC * NUM_ENDPOINTS] >>> (8 - BG)));
var c1 = ConstructColour((nEndpoints[RC * NUM_ENDPOINTS + 1] >>> (8 - RG)), (nEndpoints[GC * NUM_ENDPOINTS + 1] >>> (8 - GG)), (nEndpoints[BC * NUM_ENDPOINTS + 1] >>> (8 - BG)));
if (c0 <= c1)
compressedBlock[0] = c1 | (c0 << 16);
else
compressedBlock[0] = c0 | (c1 << 16);
compressedBlock[1] = 0;
for (var i = 0; i < 16; i++)
compressedBlock[1] = compressedBlock[1] | (nIndices[i] << (2 * i));
}
return CE_OK;
}
//dword[], word, byte,byte,byte,byte[], byte[], byte, bool, bool, bool, float[], bool, byte
function CompRGBBlock(block_32, dwBlockSize,
nRedBits, nGreenBits, nBlueBits,
nEndpoints, pcIndices, dwNumPoints,
_bUseSSE2, b3DRefinement, nRefinementSteps, _pfChannelWeights,
_bUseAlpha, _nAlphaThreshold, blkPrv) {
//align 16 float
/*Rpt = new Float32Array(BLOCK_SIZE);
BlkIn = new Float32Array(BLOCK_SIZE * NUM_CHANNELS);*/
memset(Rpt, 0);
memset(BlkIn, 0);
//dword
var dwAlphaThreshold = _nAlphaThreshold;
var dwColors = 0;
//var dwBlk = new Float32Array(BLOCK_SIZE);
for (var i = 0; i < dwBlockSize; i++)
if (!_bUseAlpha || (block_32[i] >>> 24) >= dwAlphaThreshold)
dwBlk[dwColors++] = block_32[i] | 0xff000000;
// Do we have any colors ?
if (dwColors) {
var bHasAlpha = (dwColors != dwBlockSize);
if (bHasAlpha && _bUseAlpha && !(dwNumPoints & 0x1))
return FLT_MAX;
// Here we are computing an unique number of colors.
// For each unique value we compute the number of it appearences.
dwBlk.sort(QSortIntCmp);
//qsort((void *)dwBlk, (size_t)dwColors, sizeof(CMP_DWORD), QSortIntCmp);
//dword
var new_p;
//var dwBlkU = new Int32Array(BLOCK_SIZE);
var dwUniqueColors = 0;
new_p = dwBlkU[0] = dwBlk[0];
Rpt[dwUniqueColors] = 1.0;
for (var i = 1; i < dwColors; i++) {
if (new_p != dwBlk[i]) {
dwUniqueColors++;
new_p = dwBlkU[dwUniqueColors] = dwBlk[i];
Rpt[dwUniqueColors] = 1.0;
}
else
Rpt[dwUniqueColors] += 1.0;
}
dwUniqueColors++;
// switch to float
//dword
for (var i = 0; i < dwUniqueColors; i += 1) {
BlkIn[i * 4 + RC] = ((dwBlkU[i] >>> 16) & 0xff); // R
BlkIn[i * 4 + GC] = ((dwBlkU[i] >>> 8) & 0xff); // G
BlkIn[i * 4 + BC] = ((dwBlkU[i] >>> 0) & 0xff); // B
BlkIn[i * 4 + AC] = 255.0; // A
}
//var rsltC = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
CompressRGBBlockX(rsltC, BlkIn, Rpt, dwUniqueColors, dwNumPoints, b3DRefinement, nRefinementSteps,
_pfChannelWeights, nRedBits, nGreenBits, nBlueBits);
// return to integer realm
for (var i = 0; i < 3 * NUM_ENDPOINTS; i += 2)
for (var j = 0; j < 2; j++)
nEndpoints[i + j] = rsltC[i + j] & 255;
return Clstr(block_32, dwBlockSize, nEndpoints, pcIndices, dwNumPoints, _pfChannelWeights, _bUseAlpha,
_nAlphaThreshold, nRedBits, nGreenBits, nBlueBits, blkPrv);
}
else {
// All colors transparent
nEndpoints[0] = nEndpoints[2] = nEndpoints[4] = 0;
nEndpoints[1] = nEndpoints[3] = nEndpoints[5] = 0xff;
memset(pcIndices, 0xff/*, dwBlockSize*/);
return 0.0;
}
}
function ConstructColor(R, nRedBits, G, nGreenBits, B, nBlueBits) {
return (((R & nByteBitsMask[nRedBits]) << (nGreenBits + nBlueBits - (PIX_GRID - nRedBits))) |
((G & nByteBitsMask[nGreenBits]) << (nBlueBits - (PIX_GRID - nGreenBits))) |
((B & nByteBitsMask[nBlueBits]) >>> ((PIX_GRID - nBlueBits))));
}
function Clstr(block_32, dwBlockSize, nEndpoints, pcIndices, dwNumPoints,
_pfWeights, _bUseAlpha, _nAlphaThreshold,
nRedBits, nGreenBits, nBlueBits, blkPrv
) {
var c0 = ConstructColor(nEndpoints[RC * 2], nRedBits, nEndpoints[GC * 2], nGreenBits, nEndpoints[BC * 2], nBlueBits);
var c1 = ConstructColor(nEndpoints[RC * 2 + 1], nRedBits, nEndpoints[GC * 2 + 1], nGreenBits, nEndpoints[BC * 2 + 1], nBlueBits);
var nEndpointIndex0 = 0;
var nEndpointIndex1 = 1;
if ((!(dwNumPoints & 0x1) && c0 <= c1) || ((dwNumPoints & 0x1) && c0 > c1)) {
nEndpointIndex0 = 1;
nEndpointIndex1 = 0;
}
//var InpRmp = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
InpRmp[RC * 2] = nEndpoints[RC * 2 + nEndpointIndex0];
InpRmp[RC * 2 + 1] = nEndpoints[RC * 2 + nEndpointIndex1];
InpRmp[GC * 2] = nEndpoints[GC * 2 + nEndpointIndex0];
InpRmp[GC * 2 + 1] = nEndpoints[GC * 2 + nEndpointIndex1];
InpRmp[BC * 2] = nEndpoints[BC * 2 + nEndpointIndex0];
InpRmp[BC * 2 + 1] = nEndpoints[BC * 2 + nEndpointIndex1];
var dwAlphaThreshold = _nAlphaThreshold;
for (var i = 0; i < dwBlockSize; i++) {
Blk[i * 4 + RC] = ((block_32[i] & 0xff0000) >>> 16);
Blk[i * 4 + GC] = ((block_32[i] & 0xff00) >>> 8);
Blk[i * 4 + BC] = (block_32[i] & 0xff);
if (_bUseAlpha)
Blk[i * 4 + AC] = (block_32[i] >>> 24) >= dwAlphaThreshold ? 1.0 : 0.0;
}
return ClstrBas(pcIndices, Blk, InpRmp, dwBlockSize, dwNumPoints, _pfWeights, _bUseAlpha, nRedBits, nGreenBits, nBlueBits, blkPrv);
}
function ClstrBas(_Indxs, _Blk, _InpRmp, dwBlockSize, dwNumPoints, _pfWeights,
_bUseAlpha, nRedBits, nGreenBits, nBlueBits, blkPrv) {
// make ramp endpoints the way they'll going to be decompressed
var Eq = true;
//var InpRmp = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
Eq = MkWkRmpPts(Eq, InpRmp, _InpRmp, nRedBits, nGreenBits, nBlueBits);
// build ramp as it would be built by decompressor
//var Rmp = new Float32Array(NUM_CHANNELS * MAX_POINTS);
BldRmp(Rmp, InpRmp, dwNumPoints);
// clusterize and find a cumulative error
return ClstrIntnl(_Blk, _Indxs, Rmp, dwBlockSize, dwNumPoints, Eq, _pfWeights, _bUseAlpha, blkPrv);
}
function ClstrIntnl(_Blk, _Indxs,
_Rmp, dwBlockSize, dwNumPoints,
_ConstRamp, _pfWeights, _bUseAlpha, blkPrv) {
var Err = 0;
var rmp_l = (_ConstRamp) ? 1 : dwNumPoints;
// For each colour in the original block assign it
// to the closest cluster and compute the cumulative error
for (var i = 0; i < dwBlockSize; i++) {
if (_bUseAlpha && _Blk[i * 4 + AC] == 0){
_Indxs[i] = dwNumPoints;
blkPrv[i * 4+ RC]=0;
blkPrv[i * 4+ GC]=0;
blkPrv[i * 4+ BC]=0;
if(_bUseAlpha)
blkPrv[i * 4+ AC]=0;
}
else {
var shortest = 99999999999.0;
var shortestIndex = 0;
if (_pfWeights)
for (var r = 0; r < rmp_l; r++) {
// calculate the distance for each component
var distance = (_Blk[i * 4 + RC] - _Rmp[RC * 16 + r]) * (_Blk[i * 4 + RC] - _Rmp[RC * 16 + r]) * _pfWeights[0] +
(_Blk[i * 4 + GC] - _Rmp[GC * 16 + r]) * (_Blk[i * 4 + GC] - _Rmp[GC * 16 + r]) * _pfWeights[1] +
(_Blk[i * 4 + BC] - _Rmp[BC * 16 + r]) * (_Blk[i * 4 + BC] - _Rmp[BC * 16 + r]) * _pfWeights[2];
if (distance < shortest) {
shortest = distance;
shortestIndex = r;
}
}
else
for (var r = 0; r < rmp_l; r++) {
// calculate the distance for each component
var distance = (_Blk[i * 4 + RC] - _Rmp[RC * 16 + r]) * (_Blk[i * 4 + RC] - _Rmp[RC * 16 + r]) +
(_Blk[i * 16 + GC] - _Rmp[GC * 16 + r]) * (_Blk[i * 4 + GC] - _Rmp[GC * 16 + r]) +
(_Blk[i * 16 + BC] - _Rmp[BC * 16 + r]) * (_Blk[i * 4 + BC] - _Rmp[BC * 16 + r]);
if (distance < shortest) {
shortest = distance;
shortestIndex = r;
}
}
blkPrv[i * 4+ RC]=_Rmp[RC * 16 + shortestIndex];
blkPrv[i * 4+ GC]=_Rmp[GC * 16 + shortestIndex];
blkPrv[i * 4+ BC]=_Rmp[BC * 16 + shortestIndex];
if(_bUseAlpha)
blkPrv[i * 4+ AC]=255;
Err += shortest;
// We have the index of the best cluster, so assign this in the block
// Reorder indices to match correct DXTC ordering
if (shortestIndex == dwNumPoints - 1)
shortestIndex = 1;
else if (shortestIndex)
shortestIndex++;
_Indxs[i] = shortestIndex;
}
}
return Err;
}
//float[], float[], float[], int, byte, bool, byte, float[], byte, byte, byte
function CompressRGBBlockX(_RsltRmpPnts, _BlkIn, _Rpt, _UniqClrs, dwNumPoints, b3DRefinement, nRefinementSteps, _pfWeights,
nRedBits, nGreenBits, nBlueBits) {
//align 16 float
/*var Prj0 = Prj0;
var Prj = Prj;
var PrjErr = PrjErr;
var LineDir = LineDir;
var RmpIndxs = RmpIndxs;
var LineDirG = LineDirG;
var PosG = PosG;
var Blk = Blk;
var BlkSh = BlkSh;
var LineDir0 = LineDir0;
var Mdl = Mdl;
var rsltC = rsltC;*/
var i, j, k;
// down to [0., 1.]
for (i = 0; i < _UniqClrs * 4; i += 4)
for (j = 0; j < 3; j++)
Blk[i + j] = _BlkIn[i + j] / 255.0;
var isDONE = false;
// as usual if not more then 2 different colors, we've done
if (_UniqClrs <= 2) {
for (j = 0; j < 3; j++) {
rsltC[j * 2] = _BlkIn[j];
rsltC[j * 2 + 1] = _BlkIn[(_UniqClrs - 1) * 4 + j];
}
isDONE = true;
}
if (!isDONE) {
// This is our first attempt to find an axis we will go along.
// The cumulation is done to find a line minimizing the MSE from the input 3D points.
var bSmall = FindAxis(BlkSh, LineDir0, Mdl,/* ref*/true, Blk, _Rpt, 3, _UniqClrs);
// While trying to find the axis we found that the diameter of the input set is quite small.
// Do not bother.
if (bSmall) {
for (j = 0; j < 3; j++) {
rsltC[j * 2 + 0] = _BlkIn[0 * 4 + j];
rsltC[j * 2 + 1] = _BlkIn[(_UniqClrs - 1) * 4 + j];
}
isDONE = true;
}
}
// GCC is being an awful being when it comes to goto-jumps.
// So please bear with this.
if (!isDONE) {
var ErrG = 10000000.0;
//var PrjBnd = new Float32Array(NUM_ENDPOINTS);
//align16 float
//var PreMRep = new Float32Array(MAX_BLOCK);
for (j = 0; j < 3; j++)
LineDir[j] = LineDir0[j];
// Here is the main loop.
// 1. Project input set on the axis in consideration.
// 2. Run 1 dimensional search (see scalar case) to find an (sub) optimal pair of end points.
// 3. Compute the vector of indexes (or clusters) for the current approximate ramp.
// 4. Present our color channels as 3 16DIM vectors.
// 5. Find closest approximation of each of 16DIM color vector with the projection of the 16DIM index vector.
// 6. Plug the projections as a new directional vector for the axis.
// 7. Goto 1.
// D - is 16 dim "index" vector (or 16 DIM vector of indexes - {0, 1/3, 2/3, 0, ...,}, but shifted and normalized).
// Ci - is a 16 dim vector of color i.
// for each Ci find a scalar Ai such that
// (Ai * D - Ci) (Ai * D - Ci) -> min , i.e distance between vector AiD and C is min.
// You can think of D as a unit interval(vector) "clusterizer",
// and Ai is a scale you need to apply to the clusterizer to
// approximate the Ci vector instead of the unit vector.
// Solution is
// Ai = (D . Ci) / (D . D); . - is a dot product.
// in 3 dim space Ai(s) represent a line direction, along which
// we again try to find (sub)optimal quantizer.
// That's what our for(;;) loop is about.
for (; ;) {
// 1. Project input set on the axis in consideration.
// From Foley & Van Dam: Closest point of approach of a line (P + v) to a point (R) is
// P + ((R-P).v) / (v.v))v
// The distance along v is therefore (R-P).v / (v.v)
// (v.v) is 1 if v is a unit vector.
//
PrjBnd[0] = 1000.;
PrjBnd[1] = -1000.;
for (i = 0; i < MAX_BLOCK; i++)
Prj0[i] = Prj[i] = PrjErr[i] = PreMRep[i] = 0.0;
for (i = 0; i < _UniqClrs; i++) {
Prj0[i] = Prj[i] = BlkSh[i * 4 + 0] * LineDir[0] + BlkSh[i * 4 + 1] * LineDir[1] + BlkSh[i * 4 + 2] * LineDir[2];
PrjErr[i] = (BlkSh[i * 4 + 0] - LineDir[0] * Prj[i]) * (BlkSh[i * 4 + 0] - LineDir[0] * Prj[i])
+ (BlkSh[i * 4 + 1] - LineDir[1] * Prj[i]) * (BlkSh[i * 4 + 1] - LineDir[1] * Prj[i])
+ (BlkSh[i * 4 + 2] - LineDir[2] * Prj[i]) * (BlkSh[i * 4 + 2] - LineDir[2] * Prj[i]);
PrjBnd[0] = Math.min(PrjBnd[0], Prj[i]);
PrjBnd[1] = Math.max(PrjBnd[1], Prj[i]);
}
// 2. Run 1 dimensional search (see scalar case) to find an (sub) optimal pair of end points.
// min and max of the search interval
//float
var Scl = new Float32Array(NUM_ENDPOINTS);
Scl[0] = PrjBnd[0] - (PrjBnd[1] - PrjBnd[0]) * 0.125;;
Scl[1] = PrjBnd[1] + (PrjBnd[1] - PrjBnd[0]) * 0.125;;
// compute scaling factor to scale down the search interval to [0.,1]
const Scl2 = (Scl[1] - Scl[0]) * (Scl[1] - Scl[0]);
const overScl = 1 / (Scl[1] - Scl[0]);
for (i = 0; i < _UniqClrs; i++) {
// scale them
Prj[i] = (Prj[i] - Scl[0]) * overScl;
// premultiply the scale squire to plug into error computation later
PreMRep[i] = _Rpt[i] * Scl2;
}
// scale first approximation of end points
for (k = 0; k < 2; k++)
PrjBnd[k] = (PrjBnd[k] - Scl[0]) * overScl;
var Err = MAX_ERROR;
// search step
//static const CODECFLOAT stp = 0.025f;
var stp = 0.025;
// low Start/End; high Start/End
var lS = (PrjBnd[0] - 2.0 * stp > 0) ? PrjBnd[0] - 2.0 * stp : 0.0;
var hE = (PrjBnd[1] + 2.0 * stp < 1.0) ? PrjBnd[1] + 2.0 * stp : 1.0;
// find the best endpoints
//float
var Pos = new Float32Array(NUM_ENDPOINTS);
var lP, hP;
//int
var l, h;
for (l = 0, lP = lS; l < 8; l++ , lP += stp) {
for (h = 0, hP = hE; h < 8; h++ , hP -= stp) {
//float
var err = Err;
// compute an error for the current pair of end points.
err = RampSrchW(Prj, PrjErr, PreMRep, err, lP, hP, _UniqClrs, dwNumPoints);
if (err < Err) {
// save better result
Err = err;
Pos[0] = lP;
Pos[1] = hP;
}
}
}
// inverse the scaling
for (k = 0; k < 2; k++)
Pos[k] = Pos[k] * (Scl[1] - Scl[0]) + Scl[0];
// did we find somthing better from the previous run?
if (Err + 0.001 < ErrG) {
// yes, remember it
ErrG = Err;
LineDirG[0] = LineDir[0];
LineDirG[1] = LineDir[1];
LineDirG[2] = LineDir[2];
PosG[0] = Pos[0];
PosG[1] = Pos[1];
// 3. Compute the vector of indexes (or clusters) for the current approximate ramp.
// indexes
const step = (Pos[1] - Pos[0]) / (dwNumPoints - 1);
const step_h = step * 0.5;
const rstep = 1.0 / step;
const overBlkTp = 1.0 / (dwNumPoints - 1);
// here the index vector is computed,
// shifted and normalized
var indxAvrg = (dwNumPoints - 1) / 2.0;
for (i = 0; i < _UniqClrs; i++) {
var del;
//int n = (int)((b - _min_ex + (step*0.5f)) * rstep);
if ((del = Prj0[i] - Pos[0]) <= 0)
RmpIndxs[i] = 0.0;
else if (Prj0[i] - Pos[1] >= 0)
RmpIndxs[i] = (dwNumPoints - 1);
else
RmpIndxs[i] = Math.floor((del + step_h) * rstep);
// shift and normalization
RmpIndxs[i] = (RmpIndxs[i] - indxAvrg) * overBlkTp;
}
// 4. Present our color channels as 3 16DIM vectors.
// 5. Find closest aproximation of each of 16DIM color vector with the pojection of the 16DIM index vector.
var Crs = new Float32Array(3), Len, Len2;
for (i = 0, Crs[0] = Crs[1] = Crs[2] = Len = 0.0; i < _UniqClrs; i++) {
const PreMlt = RmpIndxs[i] * _Rpt[i];
Len += RmpIndxs[i] * PreMlt;
for (j = 0; j < 3; j++)
Crs[j] += BlkSh[i * 4 + j] * PreMlt;
}
LineDir[0] = LineDir[1] = LineDir[2] = 0.0;
if (Len > 0.0) {
LineDir[0] = Crs[0] / Len;
LineDir[1] = Crs[1] / Len;
LineDir[2] = Crs[2] / Len;
// 6. Plug the projections as a new directional vector for the axis.
// 7. Goto 1.
Len2 = LineDir[0] * LineDir[0] + LineDir[1] * LineDir[1] + LineDir[2] * LineDir[2];
Len2 = Math.sqrt(Len2);
LineDir[0] /= Len2;
LineDir[1] /= Len2;
LineDir[2] /= Len2;
}
}
else // We was not able to find anything better. Drop dead.
break;
}
// inverse transform to find end-points of 3-color ramp
for (k = 0; k < 2; k++)
for (j = 0; j < 3; j++)
rsltC[j * 2 + k] = (PosG[k] * LineDirG[j] + Mdl[j]) * 255.0;
}
// We've dealt with (almost) unrestricted full precision realm.
// Now back to the dirty digital world.
// round the end points to make them look like compressed ones
var inpRmpEndPts = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
MkRmpOnGrid(inpRmpEndPts, rsltC, 0.0, 255.0, nRedBits, nGreenBits, nBlueBits);
// This not a small procedure squeezes and stretches the ramp along each axis (R,G,B) separately while other 2 are fixed.
// It does it only over coarse grid - 565 that is. It tries to squeeze more precision for the real world ramp.
if (b3DRefinement)
Refine3D(_RsltRmpPnts, inpRmpEndPts, _BlkIn, _Rpt, _UniqClrs, dwNumPoints, _pfWeights, nRedBits, nGreenBits, nBlueBits, nRefinementSteps);
else
Refine(_RsltRmpPnts, inpRmpEndPts, _BlkIn, _Rpt, _UniqClrs, dwNumPoints, _pfWeights, nRedBits, nGreenBits, nBlueBits, nRefinementSteps);
}
//float[], float[], float[], p bool, float[], float[], int, int
function FindAxis(_outBlk, fLineDirection,
fBlockCenter, _pbSmall, _inpBlk,
_inpRpt, nDimensions, nNumColors) {
var Crrl = new Float32Array(NUM_CHANNELS);
var RGB2 = new Float32Array(NUM_CHANNELS);
fLineDirection[0] = fLineDirection[1] = fLineDirection[2] = RGB2[0] = RGB2[1] = RGB2[2] =
Crrl[0] = Crrl[1] = Crrl[2] = fBlockCenter[0] = fBlockCenter[1] = fBlockCenter[2] = 0;
// sum position of all points
var fNumPoints = 0;
for (var i = 0; i < nNumColors; i++) {
fBlockCenter[0] += _inpBlk[i * 4 + 0] * _inpRpt[i];
fBlockCenter[1] += _inpBlk[i * 4 + 1] * _inpRpt[i];
fBlockCenter[2] += _inpBlk[i * 4 + 2] * _inpRpt[i];
fNumPoints += _inpRpt[i];
}
// and then average to calculate center coordinate of block
fBlockCenter[0] /= fNumPoints;
fBlockCenter[1] /= fNumPoints;
fBlockCenter[2] /= fNumPoints;
for (var i = 0; i < nNumColors; i++) {
// calculate output block as offsets around block center
_outBlk[i * 4 + 0] = _inpBlk[i * 4 + 0] - fBlockCenter[0];
_outBlk[i * 4 + 1] = _inpBlk[i * 4 + 1] - fBlockCenter[1];
_outBlk[i * 4 + 2] = _inpBlk[i * 4 + 2] - fBlockCenter[2];
// compute correlation matrix
// RGB2 = sum of ((distance from point from center) squared)
// Crrl = ???????. Seems to be be some calculation based on distance from point center in two dimensions
for (var j = 0; j < nDimensions; j++) {
RGB2[j] += _outBlk[i * 4 + j] * _outBlk[i * 4 + j] * _inpRpt[i];
Crrl[j] += _outBlk[i * 4 + j] * _outBlk[i * 4 + (j + 1) % 3] * _inpRpt[i];
}
}
// if set's diameter is small
var i0 = 0, i1 = 1;
var mxRGB2 = 0;
var k = 0, j = 0;
var fEPS = fNumPoints * EPS;
for (k = 0, j = 0; j < 3; j++) {
if (RGB2[j] >= fEPS)
k++;
else
RGB2[j] = 0.0;
if (mxRGB2 < RGB2[j]) {
mxRGB2 = RGB2[j];
i0 = j;
}
}
var fEPS2 = fNumPoints * EPS2;
_pbSmall = true;
for (j = 0; j < 3; j++)
_pbSmall &= (RGB2[j] < fEPS2);
if (_pbSmall) // all are very small to avoid division on the small determinant
return true;
if (k == 1) // really only 1 dimension
fLineDirection[i0] = 1.;
else if (k == 2) // really only 2 dimensions
{
i1 = (RGB2[(i0 + 1) % 3] > 0.0) ? (i0 + 1) % 3 : (i0 + 2) % 3;
var Crl = (i1 == (i0 + 1) % 3) ? Crrl[i0] : Crrl[(i0 + 2) % 3];
fLineDirection[i1] = Crl / RGB2[i0];
fLineDirection[i0] = 1.;
}
else {
var maxDet = 100000.0;
var Cs = new Float32Array(3);
// select max det for precision
for (j = 0; j < nDimensions; j++) {
var Det = RGB2[j] * RGB2[(j + 1) % 3] - Crrl[j] * Crrl[j];
Cs[j] = Math.abs(Crrl[j] / Math.sqrt(RGB2[j] * RGB2[(j + 1) % 3]));
if (maxDet < Det) {
maxDet = Det;
i0 = j;
}
}
// inverse correl matrix
// -- -- -- --
// | A B | | C -B |
// | B C | => | -B A |
// -- -- -- --
var mtrx1 = new Float32Array(2 * 2);
var vc1 = new Float32Array(2);
var vc = new Float32Array(2);
vc1[0] = Crrl[(i0 + 2) % 3];
vc1[1] = Crrl[(i0 + 1) % 3];
// C
mtrx1[0] = RGB2[(i0 + 1) % 3];
// A
mtrx1[3] = RGB2[i0];
// -B
mtrx1[2] = mtrx1[1] = -Crrl[i0];
// find a solution
vc[0] = mtrx1[0] * vc1[0] + mtrx1[1] * vc1[1];
vc[1] = mtrx1[2] * vc1[0] + mtrx1[3] * vc1[1];
// normalize
vc[0] /= maxDet;
vc[1] /= maxDet;
// find a line direction vector
fLineDirection[i0] = 1.;
fLineDirection[(i0 + 1) % 3] = 1.;
fLineDirection[(i0 + 2) % 3] = vc[0] + vc[1];
}
// normalize direction vector
var Len = fLineDirection[0] * fLineDirection[0] + fLineDirection[1] * fLineDirection[1] + fLineDirection[2] * fLineDirection[2];
Len = Math.sqrt(Len);
for (j = 0; j < 3; j++)
fLineDirection[j] = (Len > 0.0) ? fLineDirection[j] / Len : 0.0;
return _pbSmall;
}
function RampSrchW(_Blck,
_BlckErr,
_Rpt,
_maxerror, _min_ex, _max_ex,
_NmbClrs,
_block) {
error = 0;
step = (_max_ex - _min_ex) / (_block - 1);
step_h = step * 0.5;
rstep = 1.0 / step;
for (var i = 0; i < _NmbClrs; i++) {
var v;
// Work out which value in the block this select
var del;
if ((del = _Blck[i] - _min_ex) <= 0)
v = _min_ex;
else if (_Blck[i] - _max_ex >= 0)
v = _max_ex;
else
v = Math.floor((del + step_h) * rstep) * step + _min_ex;
// And accumulate the error
var d = (_Blck[i] - v);
d *= d;
var err = _Rpt[i] * d + _BlckErr[i];
error += err;
if (_maxerror < error) {
error = _maxerror;
break;
}
}
return error;
}
function MkRmpOnGrid(_RmpF, _MnMx,
_Min, _Max, nRedBits, nGreenBits, nBlueBits) {
var Fctrs0 = Fctrs;
var Fctrs1 = Fctrsr;
for (var j = 0; j < 3; j++) {
for (var k = 0; k < 2; k++) {
_RmpF[j * 2 + k] = Math.floor(_MnMx[j * 2 + k]);
if (_RmpF[j * 2 + k] <= _Min)
_RmpF[j * 2 + k] = _Min;
else {
_RmpF[j * 2 + k] += Math.floor(128.0 / Fctrs1[j]) - Math.floor(_RmpF[j * 2 + k] / Fctrs1[j]);
_RmpF[j * 2 + k] = Math.min(_RmpF[j * 2 + k], _Max);
}
_RmpF[j * 2 + k] = Math.floor(_RmpF[j * 2 + k] / Fctrs0[j]) * Fctrs0[j];
}
}
}
function Refine3D(_OutRmpPnts,
_InpRmpPnts,
_Blk, _Rpt,
_NmrClrs, dwNumPoints, _pfWeights,
nRedBits, nGreenBits, nBlueBits, nRefineSteps) {
var Rmp = new Float32Array(NUM_CHANNELS * MAX_POINTS);
var Blk = new Float32Array(MAX_BLOCK * NUM_CHANNELS);
for (var i = 0; i < _NmrClrs; i++)
for (var j = 0; j < 3; j++)
Blk[i * 4 + j] = _Blk[i * 4 + j];
var fWeightRed = _pfWeights ? _pfWeights[0] : 1.0;
var fWeightGreen = _pfWeights ? _pfWeights[1] : 1.0;
var fWeightBlue = _pfWeights ? _pfWeights[2] : 1.0;
// here is our gri
var InpRmp0 = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
var InpRmp = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
for (var k = 0; k < 2; k++)
for (var j = 0; j < 3; j++)
InpRmp0[j * 2 + k] = InpRmp[j * 2 + k] = _OutRmpPnts[j * 2 + k] = _InpRmpPnts[j * 2 + k];
// make ramp endpoints the way they'll going to be decompressed
// plus check whether the ramp is flat
var Eq;
var WkRmpPts = new Float32Array(NUM_CHANNELS * NUM_ENDPOINTS);
//eq ptr
Eq = MkWkRmpPts(Eq, WkRmpPts, InpRmp, nRedBits, nGreenBits, nBlueBits);